Relay foe rectifying flow of fluids



Feb. 20, 1951 F. M. POOLE ETAL 2,542,250

RELAY FOR RECTIFYING FLOW 0F FLUIDS THROUGH CONTROL VALVES Filed May 5, 1946 3 Sheets-Sheet l INVEN R5 I F. M. POOLE, AND BY H. B. MANLEY ATTORNEYS Feb. 20, 1951 F. M. POOLE ETAL 2,542,260 RELAY FOR RECTIFYING FLOW OF mums THROUGH CONTROL VALVES Filed May 3, 1946 3 Sheets-Sheet 2 DOWNSTREAM VALVE PRESSURE lllllllllllll F. M. POOLE ETAL 2,542,260 7 RELAY FOR RECTIFYING FLOW OF FLUIDS Feb. 20, 1951 THROUGH CONTROL VALVES 3 Sheets-Sheet 3 Filed May 3, 1946 Patented Feb. 20, 1951 OFFICE RELAY FOR RECTIFYING FLOW OF FLUIDS THROUGH CDNTROLv VALVES Foster M. Poole, Dallas, Ten, and Humes B. Manley, Kansas City, Mo.

Application May 3, 1946, Serial N0. 666,898

11 Claims.

This invention relates to relays for rectifying flow of fluids through control valves, wh ch valves are operated responsive to temperature, flow pressure, liquid level, or other variable factors. In valves of this character, it is impossible to reflect equal increments of deviation of the controlling factor in equal percentage increments of flow change in the fluid flowing through the control valve over the entire range of valve operation.

It is, therefore, the principal object of the present invention to provide a relay mechanism to translate equal increments of deviation in the controlling factor into substantially equal percentage increments of flow change of the controlled fluid.

Other objects of the invention are to provide a re ay device of this character that is of simple construction, reliable in operation, and which automatically compensates for control valve inertia, sticking valve stems, foreign matter in the valve, worn and distorted inner valves, and similar difiiculties ordinarily tending to interfere with proper functioning of a valve.

A further object of the invention is to permit use of less expensive control. valves and at the same time obtain the desired change in ratio between the controlling factor and the flow through the valve.

It is also an object of the invention to provide a relay for translating movement of the actuating element of a control instrument to the pressure control medium of a pressure actuated valve.

In accomplishing these and other objects of the invention hereinafter pointed out, We have provided improved structure, the preferred form of which is illustrated in the accompanying drawings wherein:

Fig. l is a side elevational view of a relay embodying the features of the present inventon.

Fig. 2 is a diagrammatic view of the relay con nected with a valve controlling flow of fuel to the burner.

Fig. 3 is an enlarged section through the relay on the line 3-2- of Fig. 4.

Fig. i is a cross section through the relay on the line i-d of Fig. 3. i

Fig. 5 is a longitudinal section through th relay. i

Fig. 6 is a perspective view of the flapper valve arm assembly.

Fig. 7 is a similar View or" the assembly from the opposite side.

Fig. 8 is a section through the vent port and flapper valve.

Fig. '9 is a graph showing the relationship of instrument pressure to the downstream valve pressure.

Referring more in detail to the drawings:

i designates a burner nozzle such as used in furnaces and the like and which is supplied with fuel; for example, gas, through a pipe 2 under control of a valve 3 which is actuated by a diaphragm motor 4 under control of an actuating instrument 5. The instrument 5 may be temperature responsive so as to maintain predetermined temperature conditions in the furnace by automatically controlling the flow of fuel thereto.

As above mentioned, in a control system of this character, equal increments of deviation in the control valve are not reflected in equal percentage increments of flow change in the gas; flowing through the control valve over the entire range of valve regulation. This is true even though valve positioners or characterized inner Valves are used in the control valve.

This difliculty is overcome in the present invention through provision of .a relay generally designated 6 including a housing 1 comprising end sections 8 and 9 and intermediate sections ll H and !2 connected together by suitable fastening devices such as cap screws l3. The end section 8 and adjacent section ill have coaxial chambers l4 and i5 respectively separated by a flexible diaphragm It. The marginal edge of the diaphragm is clamped between rings I1 and 13 inserted Within shoulder-like grooves 19 and Z0 encircling the respective chambers so that the diaphragm is adapted to be moved responsive to actuations of the control instrument 5 as transmitted through a pressure medium such as .air in a pipe 2| having inlet into the chamber Ml through a port 22. The pressure acting in the chamber l4 may be indicated by a pressure gauge 23 having connection with the port 24 opening into the chamber [4 as best shown in Fig. 5. In order to return the diaphragm upon drop of pressure in the chamber M, the diaphragm carries an axial stem 25 having a head 26 fixed thereon for connection with one end 2i of a coil spring 28 and which has its opposite end 29 secured in an anchor member 30 seated on the outer end of a tubular spring housing 3! which is adjustably threaded into an axial bore 32 of the end section 8 of the housing so as to regulate action of the spring. The tubular spring housing 3! is retained in adjusted position by means of a jamb nut 33 threaded thereon and engaging the end of the housing section 8. The spring anchoring member 30 is retained in fixed position on the end of the tubular spring housing by a cap 34 which clamps a flange 35 on the anchor member 39 against the end of the spring housing. The diaphragm stem 25 extends through a bushing 36 in the axis of the section 19 and projects within a flapper valve compartment 31 in the central section II to carry a cam member 38 which, in the illustrated instance is of cone shape and has a linear contour to give a proportional lateral position to a valve supporting arm 39 in accordance with variation of the actuating pressure in the chamber [4. Thus, when the instrument causes the pressure fluid to move the diaphragm against action of the spring, the cam member 38 is moved in one direction within the compartment 31 and when the pressure from the instrument is relieved, the spring is efiective to efiect return of the conelike cam member 38 in the opposite direction. Thus, the cone-like cam is positioned longitudinally within the com artment 39 in exact conformity with the requirements of the control instrument 5.

The conical cam member 38 is utilized in association with a cam element 40 to regulate pressure of an actuating medium on the diaphragm motor 4 of the control valve 3. The actuating pressure medium for the diaphragm motor 4 is supplied through a pine 4| which connects with a channel 42 in the section I 2 of the rela housing which in turn is connected by a channel 43 with a port 44 that is formed in the bottom of a counterbore 45 also formed in the section l2 to mount a needle valve 46. The needle valve is carried in a bushing 41 threaded into the counterbore and which is sealed with respect tothe channel 52 is connected by a pipe 53 with the dia hragm motor 4 of the valve.

The housing section [2 has a recess 54 opening from the end thereof adjacent the end section 9 of the housing and which terminates in an, an-

\ nular shoulder 55 encircling a diaphragm chamber 59. Seated on the shoulder is a clamping ring 51 cooperating with the clamping ring 58 ,for anchoring a flexible diaphragm 59 therebetween and to close the outer side of the chamber 56. Also inserted within the recess 54 is a partition member 69 that has recesses BI and 62 on the respective sides thereof to respectively accommodate movement of the diaphragm 59 and a diaphragm E3. The diaphragm 63 is similarly clamped between rings 64 and 65 and the parts are secured in assembly by fastening devices such as cap screws 66. The diaphragms 59 and 53 are backed on their respective sides by plates 61 and are spaced apart by a sleeve 68 that is slidable longitudinally in a bearing 69 carried in the partition. The plates are retained in clamping engagement with the diaphragms and with the spacing sleeve by a fastening device that extends through axial openings in the respective plates and diaphragm and through the sleeve to anchor a stem H similarto the stem previously described. The stem H is connected with a coil spring 12 that is enclosed within a tubular spring housing 13 and is anchored at the outer end to the spring housing in the same manner as the spring housing previously described. The springhousing 13 is also adjustable within the end section 9 to varyaction of the spring on the diaphragms 59 and 63.

The diaphragm chamber 56 is connected by a channel 14 shown in dotted lines (Fig. 4) and which opens into a counterbore l5 alongside the counterbore 45. The counterbore 15 also accommodates a process synchronizing needle valve 19 mounted in the same manner as the needle Valve previously described and which controls flow through a port 1'! in the bottom of the counterbore and which connects through a channel 18 with a supply channel l9 that in turn is connected through a channel 89 with the counterbore 45. The channel 19 is also connected with the counterbore 15 by a channel 81. The connection of the channels 18, 19 and Bi are controlled by a plug valve SLwhereby full pressure of the fluid may be supplied from the supply channel 19 to the chamber 51 and after a few seconds delay to the chamber 6| or vice versa depending upon the type of motor actuated valve 3. The setting of the valve illustrated is for a reverse acting diaphragm motor valve, pressure medium being supplied through port 11 and channel 19' under full pressureto the chamber 59 and in restricted flow to the chamber 6| through the port 11, channels 8! and channel 14. The other setting of the three-way valve is for a direct acting diaphragm motor valve 3 and in this setting the supply channel 19 is directly connected with the channel 8! to supply pressure through the channel 14 while restricted ing section 12 and a stem 89 of the cam member 49. The opposite end of the stem 89 carries a washer-like head 99 that is retained thereon by a cap screw 9| and which abuts against the cap screw 10 previously described, the heads of the cap screws being retained in contact by a coil spring 92 that is sleeved over the stem 89 and which has one end bearing against the washer and its opposite end in the recess in the bottom of the housing section l2. 7

The end section 9 of the housing also has a pressure chamber 93 which is connected through a port 94 with a pipe 95 leading to and connecting with the gas supply pipe 2 on the downstream side of the control valve 3 whereby pressure of the gas on the downstream side of the control sure on the other side. Under these conditions.

the downstream flow of gas through the pipe 2 is proportional to the square root of the control valve downstream gas pressure. The cam member 49 is, therefore, provided with a square root shaped contour to cooperate with the linear surface contour of the other cam member in controlling pressure of the diaphragm motor actuating fluid so as to translate equal increments of deviation in the control instrument 5 into substantially equal percentage increments of flow change in the gas as now to be described.

Formed substantially midway of the length of the central housing section II is an internally threaded bore 9! that mounts a threaded body member 93 carrying a spindle 93 of smaller diameter to form a tapered shoulder I in encircling relation with the spindle The spindle '39 projects within the chamber 31 and mounts a hub IGI of the arm 33 having one end I32 extending in the direction of the cam .member 38 and an opposite end I03 extending in the direction of the cam member 43. Adjusta'bly carried by the end I32 of the arm is a pin I34 having a ball end IE5 for engaging the linear surfaces of the cam member 38 as shown in Fig. 1 whereby the arm is positioned on the spindle responsive to positioning of the cam member 33 by the instrument 5. The end I63 has a longitudinal bore I that connects with an axial bore I36 in the hub Ifli which in turn connects with a bore H31 in the spindle 39. The spindle bore 107 connects through a lateral port I38 with an annular recess I39 that is formed circumferentially of the threaded body member 93 of the spindle to assure interconnection of the port 533 with a channel I I3 which connects with the bore K 52 previously described. Therefore, a portion of the actuating medium delivered to the motor diaphragm of the control valve is passed through the channel H3, port I38, bores It and 35 for escape through a lateral vent port IiI which is formed in the flattened side H2 of a nozzle member I113, which member is mounted on a reduced extension II -l of the arm and which is clamped against a shoulder II3 by a nut I is best shown in Figs. 6 and '7. The upper end of the bore in the hub tilt is closed by a plug i211 having a conical seat IZI for mounting an arm I22. The arm I22 is preferably formed of fiat material and has one end bent to form a boss-like loop I23 adapted to contain a coil spring I23 therein and l which has one end I25 anchored to the arm I22 and the other end anchored to a spindle 23 that is carried by the plug I33. The arm is retained in contact with the conical head of the plug by a washer I27 backed by a jamb nut I23. The end of the spindie preferably has a socket I23 for containing an antifriction ball I33 that is carried by an adjusting screw I3I adjustably threaded into a bore 32 in axial alignment with the bore 3? on the opposite side of the housing section as best shown in Fig. 3. The arm i22 extends outwardly over the end I33 of the arm 39 and carries a depending valve flap i33 that is adapted to close the vent port when the arms are substantially in parallel registry as shown in Fig. 7. In order to adjust the position of the arm i22 with respect to the square root surface of the cam member 43, the arm I 22 has an angularly extending lug I34 adjustably carrying a threaded screw 35 having a ball end I35 for engaging the square root surface of the cam 1ne1nber iii. The screw I34 on the arm 35 kept in yielding contact with the linear surface of the cam member 38 by a coil spring I37 having one end i33 engagirr a side of the arm and its opposite end I33 anchored to an opening in the central housing I I. With this construction, it is obvious that the spring I31 retains the screw I34 on the arm in contact with the cam member 33 so as to maintain relational position of the vent port III, in the opposite end of the arm relatively to the valve flapper I33 which in turn is positioned by the point on which the ball end of the screw I35 engages the square root surface of the cam member 43. The chamber 37 in the housing section I I is provided with a vent I in the side thereof for releasing the pressure me dium vented through the vent port as now to be described. The downstream control valve pres sures in the diaphragm chamber 33 are to be noted on a gauge MI and the pressures in the chamber 56 are noted on a gauge I32.

Assuming that the relay is assembled as described, it is installed between the control instrument and adjacent to the diaphragm motor control valve. Gas or air under pressure can be used as a source of power to operate the motor valve. If gas is used the vent I33 is connected with the furnace, thereby burning up gas discharged through the nozzle port HI. In operation, the control instrument 5 effects positioning of the cam 38 through the actuating pres-- sure medium acting on the diaphragm I6 through the pipe 25. As the cam member 38 is moved longitudinally within the compartment 39 the contour thereof causes the arm 33 to swing in a ciockwise direction (Fig. 1) proportionate to the pressure effected by the control instrument to effect a proportional lateral position of the nozzle H3. The cam member 33 effects similar positioning of the valve flapper I33, the cam member Lit being positioned responsive to the flow pressure on the downstream side of the control valve acting through the pipe on the diaphragm 33 which shifts the cam member 43 against action of the spring I2 and influenced by pressure differential occurring in the respective sides of the diaphragm 59. Upon initial movement, the pressure acting in the chamber 53 on the lefthand side of the diaphragm 53 is at full pressure of the diaphragm motor valve actuating medium which acts in opposition to the pressure of the gas on the downstream side of the control valve. The pressure in the chamber 53 is opposed by the pressure acting on the opposite side of the diaphragm 53 through the resistance eifected by the process synchronizing valve 75. The cam member 43, therefore, takes a longitudinal position proportional to the algebraic sum of the nozzle pressure differential across the diaphragm 59 and downstream diaphragm motor controlled pressure and in doing so a lateral position is given to the valve flapper accordance with the square root surface of the cam member 35. The pressure differential within the chambers 53 and GI is finally reduced to zero. If the momentary position of the valve flapper I33 does not cover the vent port Ii suificiently to balance the air vented through the nozzle against the air supplied through the resistance effected by the valve 33, the air pressure on the top side of the diaphragm motor control valve is changed varying the control valve downstream pressure until such equilibrium is established. When this equilibrium exists the relationship of the instrument air pressure to the downstream control valve pressure will follow the curve shown in Fig. 9.

By using the clamping rings having different inner diameters, the effective areas of the diaphragms will be varied and practically any range of the downstream control valve fluid pressures can be used in combination with the standard range of control instrument air pres- 7 cold oil or water flowing through a control valve thence to a heat exchanger having a constant pressure drop, the heat input is regulated by the valve and is not proportional to the control valve downstream pressure but is proportional to the control valve inner valve position. The relay may be used in this connection by substituting air pressure on top of the diaphragm motor control valve instead of the control valve downstream pressure.

From the foregoing it is obvious that I have provided a relatively simple apparatus for translating equal increments of pressure change from a control instrument to equal percentage increments of flow change through the diaphragm motor valve.

It is also obvious that the relay constructed and assembled in accordance with the present invention provides an interconnection between the control instrument and the pressure actuated valve so that there is no hazard brought about through leaking of the controlled fluid to the control instrument.

What we claim and desire to secure by Letters Patent is:

1. A relay including a housing having a diaphragm chamber at one end and a pluralit f diaphragm chambers at the other end, diaphragms in said chambers, a cam connected with the diaphragm in the first named chamber, a cam connected with the diaphragms in the last named chambers, a pivoted member having contact with the first named cam and provided with a vent opening, and a flap member pivoted coaxially with the pivoted member and having contact with the other cam member for opening and closing the vent opening responsive to movement of the ca members by said diaphragms. 2. A relay including a housing having a dia phragm chamber at one end and a plurality of diaphragm chambers at the other end, diaphragms in said chambers, a linear cam connected with the diaphragm in the first named chamber, a cam having a square root surface connected with the diaphragm in the last named chambers, a pivoted member having contact with the linear cam and having a vent opening, and a flap member pivoted coaxially with the pivoted member and having contact with the cam having the square root surface for opening and closing the vent opening responsive to movement of the cam members by said diaphragms.

'3. A relay including a housing having a diaphragm chamber at one end and a plurality of diaphragm chambers at the other end, diaphragms in said chambers, a linear cam connected with the diaphragm in the first named chamber, a cam having a square root surface connected with the diaphragms in the last named chambers, a pivoted member having contact with the linear cam and'having a vent opening, and a flap member pivoted coaxially with the pivoted member and having contact with the cam having the square root surface for opening and closing the vent opening responsive to the movement of the cam members by said diaphragms, a control instrument for applying pressure in the first named diaphragm chamber to position the linear cam, and means for applying opposing pressures to the other diaphragm chambers to position the cam having the square root surface.

4. A relay including a housing having a diaphragm chamber at one end and a plurality of diaphragm chambers at. the other end, diaphragms in said chambers, a'cam connected with the diaphragm in the first named chamber, a cam connected with the diaphragms in the last named chambers, a pivoted member having contact with the first named cam and having a vent opening, a flap member pivoted coaxially with the pivoted member and having contact with the other cam member for opening and closing the vent opening responsive to position of the cam members, means for supplying an actuating pressure medium to the first named diaphragm chamber, means for supplying an actuating pressure to one of the last named diaphragm chambers, and means for supplying a'separate fluid pressure to the pivoted member having the vent opening including means for supplying said separate fluid pressure medium to the other diaphragm chamber of the last named diaphragm chambers for opposing the actuating pressure.

5. A relay including a housing having a diaphragm chamber at one end and a plurality of diaphragm chambers at the other end, diaphragms in said chambers, a cam connected with the diaphragm in the last named chambers, a pivoted member having contact with the first named cam and having a vent opening, a spring for maintaining the pivoted member in contact with said cam, a flap member pivoted coaxially with the pivoted member and having contact with the other cam for opening and closing the vent opening responsive to movement of the cam members by said diaphragms, a spring for maintaining contact of the flap member with said other cam, means for supplying an actuating pressure to the first named diaphragm chamber, means for supplying an actuating pressure to one or" the last named diaphragm chambers, and means for supplying fluid pressure to the pivoted member having the Vent opening and to the other diaphragm chamber of the last named diaphragm chambers.

6. A relay of the character described, a pair of cam members, a housing having a diaphragm chamber, a diaphragm in said chamber, means for connecting the diaphragm with one of said cam members, said housing also having a pair of diaphragm chambers, diaphragms in the last named chambers, means interconnecting the last named diaphragms, valve members pivoted in the housing on a common axis intermediate the cam members, one of said members having a vent port and the other a flap to open and close said vent port, means on one of the valve members yieldably engaging one of the cam members, means on the other valve member yieldably engaging the other cam member, means connecting said other cam member with the interconnected diaphragms, means for supplying pressure mediumto the opposite sides of one of the interconnected diaphragms and to the valve member having the vent port, separate means for supplying separate pressure mediums to the other diaphragms to move said diaphragms in aphragms in the opposite directions, said first named pressure medium being adapted to act on its diaphragm on one side in opposite direction to the separate pressure medium acting on the interconnected. diaphragm.

7. A relay of the character described, a pair of cam members, a housing having a diaphragm chamber, a diaphragm in said chamber, means for connecting the diaphragm with one of said cam members, said housin also having a pair of diaphragm chambers, diaphragms in the last named chambers means interconnecting the last named diaphragrns, valve members pivoted in the housing on a common axis intermediate the cam members, one of said members having a vent port and the other a flap to open and close said vent port, means on one of the valve members yieldably engaging one of the cam members, means on the other valve member yieldably engaging the other cam member, means connecting said other cam member with the interconnected diaphragms, means for supplying pressure medium to the opposite sides of one of the interconnected. diaphragms and to the valve member having the vent port, separate means for supplying separate pressure mediums to the other diaphragms to move said diaphragms in one direction to position valve members through the cam members, springs for moving the diaphragms in the opposite directions, said first named pressure medium being adapted to act on its diaphragm on one side in opposite direction to the separate pressure medium acting on the interconnected diaphragms, and means for restricting flow of said pressure medium to the opposite side or" the diaphragm.

8. A relay of the character described, a pair of cam members, a housing having a diaphragm chamber, a diaphragm in said chamber, means for connecting the diaphragm with one of said cam members, said housing also having a pair of diaphragm chambers, diaphragms in the last named chambers, means interconnecting the last named diaphragms, valve members pivoted in the housing on a common axis intermediate the cam members. one of said members having a vent port and the other a flap to open and close said vent port, means on one of the valve members yieldably engaging one of the cam members, means on the other valve member yieldably engaging the other cam member, means connecting said other cam member with the interconnected diaphragms, means for supplying pressure medium to one side of one of the interconnected diaphragms and to the valve member having the vent port, separate means for supplying separate pressure mediums to the other diaphragms to move said diaphragms in one direction to position valve members through the cam members, and springs for moving the diaphragms in the opposite directions, said first named pressure medium being adapted to act on its diaphragm on one side in opposite direction to the separate pressure medium acting on the interconnected diaphragm.

9. A relay of the character described, a pair of cam members, a housing having a pair of diaphragm chambers, diaphragms in said chambers, means interconnecting the diaphragms, valve members pivoted on a common axis intermediate the cam members, one of said members having a vent port and the other a flap to open and close said vent port, means on one of the valve members yieldably engaging one of the cam members, means on the other valve member yieldably engaging the other cam member, actuating means ccnnected with one of the cam members, means connecting said other cam member with the interconnected diaphragms, means for supplying pressure medium to the opposite sides of one of the interconnected diaphragms and to the valve member having the vent port, and separate means for supplying a separate pressure medium to move the other diaphragm in one di rection to position the valve members through th cam member connected therewith, a spring for moving the diaphragms in the opposite directions.

10. A relay oi the character described, a pair of cam members, a housing having a pair of diaphragm chambers, diaphragms in said chambers, means interconnecting the diaphragms, valve members pivoted on a common axis intermediate the cam members, one of said members having a vent port and the other a flap to open and close said vent port, means on one of the valve members yieldably engaging one of the cam members, means on the other valve member yieldably engaging the other cam member, :actuating means connected with one of the cam members, means connecting said other cam member with the interconnected diaphragms, means for supplying pressure medium to one side of one of the interconnected diaphragms and to the valve member having the vent port, means for restricting flow of said pressure medium to the opposite side of said diaphragm, separate means for supplying a separate pressure medium to the other diaphragm to move said diaphragm in one direction to position valve member actuated by the cam member associated therewith, and springs for moving the diaphragms in the opposite directions.

11. A relay including relatively movable apertured and flap members, means for moving one of the members, a fluid pressure responsive means for moving the other member, a separate fluid pressure responsive means for opposing movement of the member operated by said first named fluid pressure responsive means, means for supplying a pressure medium at the same pressure to both the apertured member and to the opposing fluid pressure res onsive means, and means for supplying a restricted supply of said pressure medium to act on the opposing means in cooperation with said first named fluid pressure responsive means whereby the opposing force effected by said opposing means is the differential be ween the pressure medium supply pressure and said restricted supply pressure.

FOSTER M. POOLE. HUMES B. MANLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date 1,897,135 Mason Feb. 14, 1933 1,988,348 Annin Jan. 15', 1935 2,050,279 Dahl Aug. 11, 1936 2,427,235 Smoot Sept. 9, 1947 OTHER REFERENCES Publication of Mason-Nelan Regulator Co., Bulletin #3000--C, page 6, Figure 6. 

